Method and apparatus for mounting terminals on a circuit board

ABSTRACT

Loose piece eyelets are wiped back and forth across the top of a tilted transfer plate having eyelet receiving holes therein. An air flow is maintained through the holes in the transfer plate to seat the eyelets in the holes. A circuit board is positioned in a press on top of an anvil plate and the loaded transfer plate is mounted on top of the circuit board. Closing of the press moves a punch plate toward the transfer plate to force the eyelets from the transfer plate into holes in the circuit board and bring the lead ends of the eyelets into engagement with anvils on the anvil plate to stake the eyelets to the circuit board. Eyelets can be staked to the circuit board in holes off center with respect to the staking tooling.

O 1 e Unite tates Patent 11 1 1 1 Berg 1 Mar. 27, 1973 54] METHOD ANDAPPARATUS FOR 2,833,091 5/1958 Whitney ..53 142 MOUNTING I AL ON A2,858,597 11 1958 Kraeiner ..29/10 CIRCUIT BOARD 2,920,740 1/ 1960Whitted ..198/33 3,085,314 4/1963 Leiching ..29/604 Inventor: Quentin g,New Cumberland, 3,129,494 4/1964 Perkins.... ....29/203 MM Pa. 3,548,36912/1970 Garver ..29/625 X 3,574,935 4/1971 Ber ..29/203 B [73] Berg New3,578,189 5 1971 Yon kers ..214/152 berland, Pa.

[22] Filed: Oct. 15, 1971 Primary Examiner-Thomas H. Eager 211 App].No.: 189,683 At'omey*mmas Hmke [57] ABSTRACT 12?}ii'fi'if'.:3:JjiijijjiiiijjfYfffif???510111501 Leeee eieee eyeleee eeeeeeee eeekeee feeeh [58] Field of Search ..29/626 203 B 203 v 625, a i heyelet 29/604 203 MM 10, 142, mg holes therein. An arr flow 18 mamtamedthrough 198/31} 214/152; 227/153: 152; 249/96; the holes in the transferplate to seat the eyelets in the 425/109 holes. A circuit board ispositioned in a press on top of an anvil plate and the loaded transferplate is mounted [56] References Cited on top of the circuit board.Closing of the press moves a punch plate toward the transfer plate toforce the UNITED STATES PATENTS eyelets from the transfer plate intoholes in the circuit 568 201 9/1896. Latham ..249/96 board and bring thelead ends of the eyelets into 572:340 12 1896 Estabrook ..425/109gagemeht with ahvhs the anvil Plate Stake the 1,053,227 2 1913Sandoz-Moritz ..53/112 eyelets t0 the Circuit board- Eyelets can bestaked to 1,062,608 5/1913 Sandoz-Moritz ..53/235 the circuit board inholes off center with respect to the 1,649,540 11/1927 Moscini ..227/153staking tooling. 2,181,573 11/1939 Bunker... ..29/211 D 2,583,615 l/l952Tobey ..227/152 12 Claims, 16 Drawing Figures PATENIFUmzmm 3722,08?

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I 5 Quenhn B g BY Thomas Ookev;

d s ornelj METHOD AND APPARATUS FOR MOUNTIN TERMINALS ON A CIRCUIT B IThe invention relates to an improved method and apparatus for rapidlyand simultaneously staking a large number of eyelets or terminals to acircuit board in a given pattern. A stream of loose piece eyelets isflowed down the top of a tilted transfer plate having eyelet receivingbores formed therethrough in the pattern in which the eyelets are to bestaked to the circuit board. An air flow is maintained through the boresto pull eyelets into the individual bores. Flexible wiping flaps lightlyengage the top of the transfer plate and are moved up and down the plateto facilitate uniform spreading of the eyelets across the plate anddisplace eyelets which are held against the eyelet receiving bores inimproper orientation. Another wiping flap is moved back and forth acrossthe plate at a distance above the plate to break up clusters of eyeletsheld above the bores by the parasitic drag of air flow through thebores. The combination of flowing the eyelets down the plate togetherwith the wiping assures rapid loading of eyelets into the bores. Onethousand eyelet receiving bores in a transfer plate area measuring 12inches by 14 inches may be loaded with 0.050 inch diameter eyelets inabout seconds. Frequently there is a small number of bores, usuallyabout three or four, which remain unfilled after loading. These boresmay be easily hand loaded by the operator.

Following loading of the transfer plate the plate is moved to a stakingpress. The eyelet receiving circuit board is mounted on an anvil platecarrying a staking anvil beneath each eyelet receiving circuit boardhole. The transfer plate is mounted above the circuit board and beneatha punch plate carrying punches arranged in the same pattern as theanvils and transfer plate bores. Closing of the press brings the punchesinto engagement with the eyelets so that the eyelets are forced from thebores and into the circuit board holes. When the press bottoms the leadends of the eyelets engage the anvils and are flared outwardly to stakethe eyelets to the circuit board.

The transfer plate bores and the staking tooling enable eyelets to bestaked to circuit board holes which are laterally offset somewhat fromthe desired or nominal hole location. The bores and staking tooling arelocated on the nominal axes of the circuit board holes so that laterallyoffset of the circuit board holes for a given distance in any directionfrom nominal axis will not prevent staking of the eyelet to the board.This feature is important since in the manufacture of productionquantities of circuit boards it is invariable that the circuit boardholes will not be located exactly at the desired location.

Another advantage of the invention relates to the fact that the eyeletsare positively driven into the circuit board holes during the stakingoperation. In circuit boards where the holes are formed by a punchingoperation fibrous strands frequently extend from the walls of the holesinto the interior of the holes to prevent directly loading the eyeletsinto the circuit board hole in the same manner as the eyelets are loadedinto the transfer plate; Staking as described drives the eyelet bodiespast the fibrous strands to stake the eyelets in the holes.

The invention is an improvement over the disclosure of my previous US.Pat. No. 3,574,935 for apparatus and method for applying terminals to acircuit board. In

that patent terminals are severed from a carrier strip and then guidedthrough individual drop tubes to desired locations on a transfer plate.The terminals are then lifted by a vacuum from the transfer plate to aram plate where they are held by a parisitic drag until they are stakedto a circuit board. With the present invention it is possible to stakemore eyelets to a circuit board more rapidly than is possible in myprior apparatus. Modification of the invention to stake eyelets tocircuit boards in a different pattern is more easily attained in thecase of the present invention than in the prior disclosure.

Other objects and features of the invention will become apparent as thedescription proceeds, especially when taken in conjunction with theaccompanying drawings of which there are six sheets.

IN THE DRAWINGS FIG. 1 is a perspective view disclosing apparatus formounting terminals on a circuit board;

FIG. 2 is a partially broken away side view of the transfer plateloader;

FIG. 3 is a view taken along line 3-3 of FIG. 2;

FIG. 4 is a partially broken away top view of the loader;

FIG. 5 is a partially broken away view taken along line 5-5 of FIG. 4following mounting of a transfer plate and extension of the wipingbrush;

FIG. 6 is a perspective view illustrating operation of the loader;

FIG. 7 is a sectional view taken along line 77 of FIG. 8 illustrating aneyelet as positioned in a hole in the transfer plate;

FIG. 8 is a top view of the terminal loaded in the transfer plate;

FIG. 9 is a partially broken away side view of the press used to stakethe eyelets carried in the transfer plate to a circuit board;

FIGS. 10, 11, 12 and 13 are enlarged views illustrating the staking ofone of the eyelets in the transfer plate;

FIGS. 14 and 15 illustrate staking of an eyelet in a circuit board holewhich is axially offset from the staking tooling; and

FIG. 16 is a top view of a circuit board hole illustrating fibersextending therein.

DESCRIPTION OF THE APPARATUS The apparatus disclosed in FIG. 1simultaneously attaches a large number of circuit board eyelets to acircuit board. The eyelets may be of the type disclosed in Olsson Pat.No. 3,504,328 which is assigned to Berg Electronics, Inc. of NewCumberland, Pennsylvania. Loading apparatus 10 is supplied with a massof loose piece eyelets which are moved over the surface of a transferplate 12 and are seated in bushings extending through the thickness ofthe transfer plate. Following loading of the transfer plate 12 the plateis removed from the loading apparatus. The circuit board 14 is mountedon an anvil plate 16 and the transfer plate is positioned above thecircuit board with each eyelet holding bushing above an eyelet receivinghole through the thickness of the circuit board. A punch plate 18 ismounted above the transfer plate.

The transfer plate, circuit board and anvil plate as sembly is thenmoved between the pressure plates of press 20. The upper pressure platecarries a punch plate 18 with punches located in axial alignment withthe eyelet carrying bushings on the transfer plate. Upon closing of thepress the punches on plate 18 are lowered into the bushings of transferplate 12 to push the eyelets confined therein into the aligned circuitboard holes. The lead ends of the eyelets extend through the circuitboard holes through the bottom of the circuit board and are flaredoutwardly by anvils on plate 16 to stake the eyelets to the circuitboard.

Closing of the press forces the eyelets through the circuit board holesdespite glass fibers or other obstructions in the holes. The stakingtooling and the somewhat rounded eyelets cooperate to stake eyelets intocircuit board holes which are laterally offset from the nominallocations.

The loading apparatus will now be described in further detail. Apparatus10 includes a base 22 having a working platform 24 on one side thereofand an eyelet loading box 26 on the other side thereof. The box 26 istilted toward the front of the apparatus 10 and is mounted on support 28extending above base 22. The loading box includes a cover 30 secured tosupport 28 by means of hinges 32 on the back of the support tofacilitate opening of the loading box. A hood 34 is attached to cover 32by slides 36 so that loading chamber 38 located beneath the hood may beopened by sliding the hood up under the cover. Strap 40 is attached tothe cover to limit rotation of the cover about hinge 32.

The eyelets 42 loaded by apparatus 10 include a generally cylindricalbody 44 having a flat multi tab flange 46 at one end thereof and arounded or bulletnosed lead-in 48 at the other end thereof.

The transfer plate 12 is provided with a number of eyelet receivingbushings 50 extending through the thickness of the plate and arranged inthe same pattern as the nominal pattern of the eyelet receiving holes incircuit board 14. Each bushing 50 is fitted in a bore 52 extendingthrough plate 12 with flange 54 seated against shoulder 56. Thecylindrical hole 58 extending through the bushing 50 has a radiusslightly less than the maximum radius of the eyelet flange 46. A bevellead-in 60 is provided at the top of holes 58 to facilitate seating ofthe eyelets 42 therein. As illustrated in FIGS. 7 and 8, when an eyeletis seated within a bushing 50 the outer edges of the flange 46 engagethe bottom of the bevel 60 immediately adjacent hole 58 and the eyeletbody 14 is positioned within the hole 58.

Transfer plate 12, as indicated in FIG. 1, is generally rectangularhaving a number of bushings 50 arranged in the desired pattern in thecenter thereof and with a pair of locating holes 62 on opposite edgesthereof located outwardly of the bushings. When the hood 34 is raisedbeneath cover 30, the transfer plate may be positioned on edges 64defining the periphery of a rectangular opening 66 in the bottom of theloading chamber 38. The opening 66 communicates the loading chamber 38with a vacuum chamber 68 immediately beneath the loading chamber. A pairof locking air cylinders 70 are mounted on the opposite side walls ofchamber 68 adjacent opening 66 with pins 72 carried by the free ends ofthe air cylinder piston rods extending through the opening 66. The plate12 is positioned over the opening 66 with pins 72 extending into holes62 following which the air cylinders are extended to move the roundededge 74 of the transfer plate against the undercut edge 76 of the plate78 which extends upwardly from the loading chamber and forms the bottomof eyelet entrance chamber 80. An eyelet feed tube 82 extends fromblower 84 past an eyelet terminal collecting pipe 86 communicating withthe bottom of the loading chamber 38 and past the loading chamber to aspout 88 extending into the top of chamber 80. A gravity trap 90 isprovided in pipe 82 between the blower and the junction with collectingpipe 86.

When the blower 84 is actuated, a blast of air is forced through pipe 82and into the chamber 80. The air blast carries loose piece eyelets 42along with it so that the eyelets are flowed along the bottom of chamber80 and across the transfer plate on the bottom of loading chamber 38.Eyelets collected in trough 92 .at the bottom of the loading chamberfall down the collecting tube to trap'90 where they are again blown uppipe 82 to chamber 80.

A pair of eyelet spreading baffles 94 and 96 extend into chamber 80 fromthe top wall thereof. Baffle 94 extends laterally slightly beyond themouth of spout 88 and is bent away from the spout at an angle so thatthe eyelets which are blown out of the spout are spread laterally of thespout and are deflected toward the plate 28. Second baffle 96 is locateddownstream of baffle 94 and extends laterally nearly the entire width ofchamber 80. The baffle is more nearly perpendicular to plate 78 thanbaffle 94 and extends nearer to plate 78. Baffle 96 serves to furtherspread the eyelets blown from spout 88 and also to deflect the same downagainst plate 78. The combination of the two baffles assures that theeyelets blown from the spout 88 are spread uniformly across the width ofthe chamber so that a uniform supply of eyelets is flowed across thetransfer plate. Chambers 38 and 80 are the same width.

Sweeping air cylinder 98 is mounted on top of the cavity 80 with thepiston rod 100 thereof extendable into the loading chamber 38. A brushassembly 102 is secured to the front end of rod 100 and includes a pairof primary eyelet sweepers 104 and a secondary sweeper 106. Each primarysweeper includes a flat flexible flap 108 carried by a support 110secured to rod 100. Flaps 108 extend across all of the bushings in thetransfer plate. The brushes 108 may be formed from a plastic or othersuitable material. The secondary sweeper 106 is spaced a distanceupstream or nearer spout 88 than the primary sweepers and includes alike flap 1 12 formed of a sheet of flexible material held by a supportwhich is connected to the primary brushes by bolts 116.

Primary sweeper flaps 108 lightly engage plates 12 and 78 so that as thebrush assembly is moved back and forth, the brushes are wiped along thesurface of the plates. The primary flaps 108 sweep a mass of eyeletsback and forth over the bushings 50. The secondary brush sweeper 112 isspaced a slight distance above plates 12 and 78 so that it does notengage the plates as the assembly 102 is moved back and forth. Thesecondary brush breaks up clusters of eyelets which may collect overbushings in plate 12.

A high capacity vacuum pump or other vacuum source (not shown) isconnected to vacuum chamber 68 through relatively large diameter vacuumpipe 118 and opening 120 provided in the bottom of the chamber. A vacuumbaffle plate 122 is spaced slightly from opening 120 in order todistribute the vacuum relatively uniformly throughout chamber 68. Thebaffle is required in view of the relatively high flow of air throughthe bushings in plate 12 into chamber 68 and through the vacuum pipe 118to the vacuum source. A pair of fluorescent lights 124 is located onopposite sides of the vacuum chamber 68 beneath plate 12.

A control rod 126 extends from plate 128 of sweeping assembly 102 backalong air cylinder 98. Two control microswitches 130 and 132 are mountedadjacent the ends of the air cylinder so that upon extension andretraction of the air cylinder, the end of the rod 126 is moved past.the triggers of the microswitch so as to open and close the switches.Mesh windows 134, illustrated in FIG. 4, are provided in the top ofcavity 80 to permit visual inspection of the chamber.

Press illustrated in FIGS. 1 and 9 includes a base 140 having a lowerpressure plate 142 mounted on the top thereof. Four posts 144 extendthrough holes in plate 142 and are attached to upper pressure plate 146.The lower ends of the posts are secured to a press mechanism (notillustrated) located within the base 140 which when actuated moves theupper pressure plate 146 toward and away from the lower pressure plate142.

A tray 148 is movable from a position to one side of the pressure plates142 and 146 as illustrated in FIG. 1 to a position between the pressureplates. When the tray is inserted between the pressure plates it restsupon the lower pressure plate 142. A pair of locating pins 150 extendfrom opposite sides of tray 148 to facilitate the mounting of thetransfer plate 12 thereon.

Punch plate 18 is provided with a number of eyelet punches 152 whichextend outwardly of the bottom surface of the plate and are arranged inthe same pattern as the pattern of the bushings 50 in transfer plate 12.While the punches 152 are illustrated in FIGS. 10 thru 15 as beingintegral with plate 18, obviously the punches may be separate insertsmounted within holes in the plate.

Each punch 152 includes a cylindrical body 154 having a reduced diametercylindrical tip 156 at the end facing away from plate 18. The body andtip of each punch 152 are located on the same axis as that of theadjacent bushing 50. As indicated in FIG. 13, the diameter of punch body154 is somewhat less than the diameter of the hole 58 in the bushing tofacilitate driving of the eyelet through the bushing during the stakingoperation. The clearance between the punch and the bore in the bushingalso facilitates retention of the eyelet flush upon shoulder 158 of thepunch adjacent tip 152 during staking.

Anvil plate 16 is provided with a pair of locating holes 160 on oppositeedges thereof so that it can be mounted on tray pins 150. A number ofstaking anvil inserts 162 are mounted in the anvil plate in the samepattern as the staking punches and bushings. Each anvil insert includesan obtuse conical staking tip 164 which is coaxial with associatedbushing and punch. The included angle on opposite diametrical sides ofthe staking tip is about 130. It is desirable to provide a staking tiphaving an obtuse angle between opposite sides to assure that the eyeletsare properly staked in off-center circuit board holes.

Circuit board 14 is mounted on pins 166 carried by anvil plate 16 sothat the circuit board is properly oriented with respect to the stakingtooling. Resilient pads 167 normally hold the board a slight distanceabove plate 16. During staking the circuit board is sandwiched betweenthe transfer plate and anvil plate to collapse the pads 167 and move thecircuit board toward the anvil plate. Metal spacers 168 on the anvilplate are provided to prevent the circuit board from resting flush uponthe top of the anvil plate.

Suitable controls including microswitches, solenoid controlled valvesand like mechanisms are provided to control the operation of apparatuses10 and 20. Some controls are illustrated in the drawings. The operationof air cylinder 98 in sweeping the brush assembly back and forth overthe transfer plate-is preferably controlled by an automatic timer setfor the required number of sweeps.

OPERATION OF THE APPARATUS Prior to the operation of loading apparatus10, an adequate supply of loose part eyelets 42 is placed in the gravitytrough 92 so that they will fall into the trap 90. At the start of thecycle of operation, hood 34 is pushed into cover 30 and an emptytransfer plate 12 is positioned over opening 66 with pins 72 extendingthrough locating holes 62 in the plate. Air cylinders are then extendedin order to force the rounded edge 74 of the plate against the undercutedge 76 of plate 78. With the transfer plate held in this manner thereis a smooth fit with plate 78 so that the eyelets are not worn as theymove from plate 78 down the transfer plate. The other three edges of thetransfer plate are seated flush upon edges 64 on the remaining threesides of opening 66. Eyelets which fall off the lower edge of thetransfer plate are collected in trough 92, and fall back down tube 86.

With the transfer plate in the loading position the hood is lowered tothe closed position and the vacuum source is actuated. The vacuum sourceprovides a pressure differential between the loading chamber 38 andvacuum chamber 68. Because initially the bushings are free of eyeletsthere is a relatively large air flow through the holes in the bushingsthus requiring a large volume vacuum source to maintain the desiredpressure dif ferential of approximately one inch of water.

Actuation of the blower 84 causes a stream of air to move through eyeletfeed tube 82 so that the eyelets are picked up from trap 90, movedthrough the tube and sprayed out of spout 88 in a stream against baffles94 and 96. The baffles serve to spread the stream of eyelets relativelyuniformly across the width of chamber in the manner previouslydescribed. After a' supply of eyelets has accumulated behind the wipingflaps of brush assembly 102, air cylinder 98 is actuated to extend andretract piston rod thereby moving the primary sweepers 104 back andforth across all of the bushings in the transfer plate. The secondarysweeper is also moved back and forth across all but the bottom-mostportion of the plate.

Movement of the sweepers permits the loose eyelets to tumble down fromplate 78 and across the upper face of the transfer plate. The air flowthrough the bushings pulls individual eyelets into holes 58 to seat thesame therein as illustrated in FIG. 7. Upward movement of the brushassembly upon retraction of air cylinder 98 moves the primary sweepersback up the surface of the transfer plate to dislodge eyelets which areheld against bushings in improper alignment. Thus the flow of airthrough a bushing could hold an eyelet against the bevel 60 with thebody of the eyelet projecting above the top of the transfer plate. Thismisoriented eyelet would be swept away by the primary sweepers thusfreeing the bushing for reception of a properly oriented eyelet.

Because of the high air flow through the bushings, there is a tendencyfor a number of eyelets to be held in a cluster against a singlebushing. Such a cluster 180 is illustrated in FIG. 5. Movement of thesecondary sweeper 106 across the transfer plate breaks up clusters 180to provide additional free eyelets so that they may be drawn into thebushings.

During loading of the transfer plate, air cylinder 98 is cycled toextend and retract a number of times sufficient to load substantiallyall of the bushings with eyelets. In the case of a transfer plate with1,000 bushings, a pressure differential across the plate of one waterinch or slightly more and a forward and back sweeping cycle of onesecond duration, it has been found that approximately 65 to 70 percentof the bushings are filled during the first sweep. Ten sweepssubstantially fills all of the bushings with the possibility thatperhaps one to five of the bushings remains unfilled. Considering thatthe eyelets are 0.050 inches in diameter, the efficiency of the loadingapparatus is immediately apparent. At least 99.5 percent of the bushingscan be filled reliably within a cycle time of 10 seconds.

As the bushings become filled during cycling of the air cylinder, theair flow through the transfer plate is reduced thereby increasing thepressure differential across the plate. In order to prevent thisincreased pressure from pulling the eyelets completely through thebushings, a pressure limiting valve 182 may be provided in one wall ofthe vacuum chamber 68. The valve opens automatically when the pressuredifferential across the transfer plate increases to about ten waterinches. A further increase in pressure would increase the parisitic dragon the eyelets so as to bend the flange tabs sufficiently to permit theeyelets to be drawn through the bushings.

During movement of the brush assembly 102 back and forth across thetransfer plate, blower 84 continuously replenishes the supply of eyeletsbehind the flaps thereby assuring that there is a supply of eyelets onthe transfer plate available to be pulled into the bushings by the airflow into the vacuum chamber. After the air cylinder 98 is cycledsufficiently to fill substantially all of the bushings with eyelets, itis retracted to the position of FIG. 2 with the brush assembly 102withdrawn into chamber 80 free of the transfer plate. The operator thenreactivitates the blower 84 and vacuum source and raises hood 34 intocover 30 and inspects the transfer plate. A brush may be used to sweepthe top of the plate to remove any eyelets not properly seated inbushings. After the plate has been swept clean, the operator is ablevisually to discern whether or not there are any unfilled bushings fromthe light passing through the bushings from bulbs 124. Such bushings maybe easily filled by the use of a hand loader. As mentioned previously,the number of sweeps of the brush assembly back and forth across thetransfer plate is determined so that during the loading operation allbut a very few of the bushings are loaded with eyelets. Since theloading is accomplished on a random basis, it is not possible to assuretotal loading.

After the operator has hand filled the unfilled bushings air cylindersare retracted to move the transfer plate free of plate 78 and permit theoperator to remove the loaded transfer plate from loading apparatus 10.After loading of the transfer plate the eyelets held therein are nextstaked to the circuit board 14. In the rest position the upper and lowerpressure plates 142 and 146 of the press 20 are spaced apart and punchplate 18 is mounted on the upper press plate 146 by a pair of pins 170.Tray 148 is withdrawn from between the pressure plates as indicated inFIG. 1. Anvil plate 16 is mounted on pins 150 extending from the bottomof the tray. Circuit board 14 is placed on the anvil plate on locatingpins 166 so that a circuit board hole 184 is positioned above each anvilinsert 162. The circuit board is held above spacers 168 by resilientcushions 167. The loaded transfer plate 12 is then loaded on top of thecircuit board on spring backed pins 169 which extend from the anvilplate. With the transfer plate mounted on pins 169 each bushing 50 islocated in axial alignment with the nominal location of a circuit boardhole 184 and the associated anvil insert 162. The spring backed pins 169hold the transfer plate slightly above the circuit board.

After the circuit board and loaded transfer plate have been mounted onthe anvil plate, the tray 148 is moved between the open press plates sothat each anvil insert, circuit board hole and bushing are in alignmentwith a punch 152. After the tray has been moved between the pressureplates to the proper position, the operator actuates the press to lowerupper press plate 146 thereby moving the punch plate down toward thetransfer plate. Descent of the upper press plate stakes the eyeletscarried by the transfer plate in the circuit board holes as illustratedin FIGS. 10 thru 13. All of the eyelets are staked to the circuit boardin the same manner.

As indicated in FIG. 10, lowering of the punch plate 18 brings punch 152toward the associated bushing 50 so that the tip 156 of the punchextends into the hollow top of the eyelet. Further lowering of the punchplate seats the shoulder 158 against the inner portion of the eyeletflange 46 and drives the eyelet down bore 58 past the bevel 60. The tipsof the flange which engage the bevel are bent around the shoulder 158into the clearance between bore 58 and punch body 154 to assure that theeyelet is held snugly against the punch during the staking'operation.The snug fit between the eyelet and punch prevents tilting of the eyeletbody during the punching operation. As illustrated in FIG.

10, the eyelet body is held against the punch so that it does not touchthe sides of the bore as it is moved toward the circuit board.

As plate 146 is lowered the transfer plate is forced down and compressespins 169 so that it rests flush upon the upper surface of circuit board14 as indicated. Lowering of the punch plate moves eyelets through thebores 58 to position the eyelet bodies 44 within the circuit board holes184. The lead end 68 provided by the bullet nose or rounded lower end ofthe eyelet body facilitates movement of the cylindrical eyelet body intothe circuit board hole. This feature is particularly important in thecase where the circuit board holes 184 are axially offset with respectto the tooling axes as will be described in connection with FIGS. 14 and15.

The punch plate 18 engages the upper surface of transfer plate 12 at thetime the punches have seated the top flange of the eyelet against thetop surface of the circuit board. This position is illustrated in FIG.11. The eyelet bodies extend through the circuit board hole with thelower lead-in end projecting outwardly of the circuit board past printedcircuitry 186. Further lowering of the upper press plate 146 moves theram plate, transfer plate and circuit board toward the fixed anvil platethereby compressing the cushions 167 and bringing the exposed end of theeyelets into engagement with the conical staking tips so that the eyeletends are flared outwardly to stake the eyelets to the circuit board.Movement of the circuit board toward the anvil plate is limited byspacers 168.

When the upper press plate has lowered sufficiently to bring the toolinginto the staking position of FIGS. 12 and 13, the press raises to returnthe upper press plate to the open position of FIG. 1. Tray 148 may thenbe removed from between the press plates and the transfer plate and thecircuit board with the eyelets staked thereto may be lifted from theanvil plate. Removal of the circuit board from the press completes thecycle of operation.

In production operation, the operator uses a pair of like transferplates 16 with loading apparatus and press 20. The first transfer plateis loaded with eyelets and then mounted on the anvil plate with acircuit board therebetween so that it may be positioned between thepress plates for staking. During the staking operation the operatormounts the second transfer plate in the loading apparatus and initiatesthe loading cycle. After staking has been completed and the press platesare again separated, the operator removes the transfer plate and stakedcircuit board from the anvil plate and repositions a new circuit boardon the anvil plate. The newly loaded transfer plate is then inspected tomake sure that all of the bushings are loaded and if necessary the emptybushings are hand loaded. This transfer plate is positioned on top ofthe circuit board and the tray is then positioned between the open pressplates and the staking cycle is initiated. The transfer plate which hasbeen removed from the press is then positioned in the loading apparatus10 and the loading cycle is started.

Through the use of two staking plates it is possible to load one of thetransfer plates with eyelets at the same time as eyelets are staked on acircuit board from the other transfer plate. In this manner, it ispossible to stake eyelets to a larger number of circuit boards than in aconventional loading and staking apparatus.

Another advantage of the invention is that during staking the eyeletsare positively seated in the circuit board holes by the punches. In anumber of instances the circuit board holes are formed in a fibrousboard by a punching operation which leaves fiber strands extending intothe interior holes from the side walls. FIG.

16 illustrates a circuit board 190 having a hole 192 formed therethroughwith a number of fiber strands 188 extending into the interior thereof.These fiber strands make it impossible to draw eyelets 42 directly intothe circuit board holes by a flow of air through the holes. The fibersare sufficiently strong to prevent the eyelet from seating in the hole.

The problem is overcome by loading eyelets in a transfer plate and thenpositively driving them into the circuit board holes by means ofpunches. The punch driven eyelets bend the strands out of the insertionpath. Additionally, because the diameter of the insert bores is somewhatlarger than the diameter of the circuit board holes, it is possible toload the transfer plate somewhat more rapidly than direct loading of theeyelets in the circuit board holes. The use of masking templates forcovering openings in the circuit board during the loading operation, areinforcing plate to prevent buckling of the circuit board and otherdevices required for loading the eyelets directly on the circuit board,are eliminated by the use of the transfer plate.

The rounded bullet nosed lead-in 48 at. the end of the eyelet isprovided to facilitate movement of the eyelet body into the circuitboard hole during the staking. When the circuit board hole is properlyaligned with the axis of the staking tooling, as illustrated in FIGS. 10thru 14, the hole is located directly beneath the eyelet body so thatupon movement of the eyelet toward the circuit board hole, the body islowered directly into the hole.

However, in some circuit boards, the eyelet hole is not exactly locatedso that the hole axis 194 is offset somewhat from the tooling axis 196.This situation is illustrated in FIGS. 14 and 15. Lowering of the punchin this situation moves the eyelet body toward the offset hole so thatthe rounded lead-in 48 engages the hole edge 198 located nearest toolingaxis 196. So long as edge 198 engages the lead-in and the hole 200 islocated within the larger diameter bushing hole 58, the lead-in willguide the eyelet body into the hole and further lowering of the punchwill seat the major portion of the eyelet flange 46 on the top of thecircuit board.

When the eyelet is seated in the hole, the lead-in projects out of thehole on the bottom of the circuit board. As the upper press platebottoms the circuit board is moved down to force the offset lead-inagainst the anvil insert so that a major portion of the insert is flaredoutwardly of the hole to stake the eyelet to the circuit board. Stakingof an eyelet in an offset circuit board hole is illustrated in FIG. 15.Staking is achieved despite the offset because the included angle of theconical staking tip 164 is relatively shallow. As mentioned previously,it is desirable that this angle be approximately During staking of theeyelets in offset circuit board holes the punch tip 156 assures that atleast part of the eyelet flange is held against the tip of the circuitboard at the edge of the hole. See FIG. 15.

While I have illustrated and described a preferred embodiment of myinvention, it is understood that this is capable of modification, and Itherefore do not wish to be limited to the precise details set forth,but desire to avail myself of such changes and alterations as fallwithin the purview of the following claims.

What I claim as my invention is:

1. Apparatus for loading terminals into bores formed in a flat platecomprising a transfer plate having terminal receiving bores formedthrough the thickness thereof and arranged in a desired pattern; atilted plate support engagable with the plate away from the bores; aloading chamber above the support and a vacuum chamber beneath thesupport; a vacuum source communicating with the vacuum chamber tomaintain the pressure in the vacuum chamber beneath that in the loadingchamber; a terminal transportation system including an entrance chambercommunicating with the loading chamber at the top of the support andhaving a lower floor forming an extension of the plate when mounted onthe support, a loose piece terminal trap, a terminal supply conduitextending from said trap to a mouth opening into the entrance chamber, aterminal return conduit joining the loading chamber at the bottom of thesupport to the trap, air pressure means for directing a flow of air pastsaid trap and through said supply conduit to pick up a number of loosepiece terminals and direct a stream of terminals through the mouth andinto the entrance chamber, and baffle means in the entrance chamber forspreading the stream of terminals across the width of the plate; and asweeping assembly including a sweeper engagable with the plate fordislodging misaligned terminals from the bores in the plate, a clusterbreaker, and means for moving said sweeper and cluster breaker back andforth across the plate.

2. Apparatus as in claim 1 wherein said sweeper comprises a pair ofclosely spaced flexible flaps having edges engaging the plate, andwherein said cluster breaker comprises a third flexible flap located adistance nearer the mouth than the sweeper.

3. Apparatus as in claim 1 including means for limiting the pressuredifferential across the board as terminals are loaded into the bores.

4. Apparatus for mounting terminals on a circuit board in a givenpattern comprising a loading chamber; a vacuum chamber communicatingwith said loading chamber; a transfer plate having terminal receivingbores therein arranged in said pattern; a plate support for locating thetransfer plate in the opening between the chambers; vacuum means forlowering the pressure in the vacuum chamber below that of the loadingpressure whereby terminals are drawn into the bores; transport means forflowing a stream of loose piece terminals through the loading chamberand across the transfer plate; a flat flexible wiping flap in theloading chamber with one edge thereof engaging the transfer plate; meansfor moving the flap back and forth across the transfer plate to dislodgemisaligned terminals from bores in the plate; and press means forforcing terminals from the transfer plate bores into holes in a circuitboard.

5. Apparatus as in claim 4 including a cluster breaker movable with saidflap and spaced a distance above the transfer plate for breaking upclusters of terminals formed thereon.

6. Apparatus as in claim 3 including means for limiting the pressuredifferential across the transfer plate as terminals are loaded into thebores therein.

7. Apparatus as in claim 4 wherein said transport means includes aclosec conduit having a terminal receiving opening in the loadingchamber to one side of the plate support, a terminal receiving trap, aterminal emitting opening at another side of the transfer plate supportand means for flowing a stream of terminals from said opening in adirection toward the transfer plate.

8. Tooling for simultaneously staking a plurality of terminals to acircuit board in a given pattern comprising a terminal loading terminalplate having a number of cylindrical bores formed through the thicknessthereof and oriented in said pattern, each bore having an increaseddiameter lead-in on one side of the terminal plate to permit an eyelettype terminal to be confined in the bore within the thickness of theterminal plate with the cylindrical body of the terminal in the bore andthe terminal flange extending beyond the bore and engaging the sides ofthe lead-in below the surface of the terminal plate; a punch plate onthe lead-in side of the terminal plate including a plurality of punches,each punch having a cylindrical body axially aligned with a bore in theterminal plate and having a diameter slightly less than the interiordiameter of the bore, a reduced diameter nose at the free end of thepunch and a locating shoulder surrounding the nose; and a staking plateon the opposite side of the terminal plate including a plurality ofconical staking anvils, each staking anvil being axially aligned with abore whereby upon positioning of a circuit board between the terminalplate and the staking plate with a circuit board hole in nominalalignment with the axis of each bore relative movement of the punchplate toward the anvil plate moves the punches into engagement with theterminals, and forces the same through the bores while seated on thelocating shoulders, positions the bodies of the terminals within circuitboard holes with the major portion of each flange seated against the topof the circuit board and stakes a major portion of the free end of theeyelet body adjacent the bottom of the circuit board.

9. A method of mounting terminals on a circuit board comprising thesteps of flowing a stream of loose piece terminals down a tiltedtransfer plate while maintaining a pressure differential across theplate to draw properly oriented individual terminals into bores in thetransfer plate, dislodging misaligned terminals held against bores as aresult of the pressure differential, and breaking up clusters ofterminals held against bores to load nearly all of the bores withterminals; manually inserting properly oriented terminals into theremaining unloaded bores to completely load the transfer plate;positioning the transfer plate in a press adjacent a circuit board withcircuit board holes in alignment with the bores; and closing the pressto force the terminals from the transfer plate into the circuit boardholes.

10. The method of mounting individual loose piece terminals in holes ina circuit board having a given pattern comprising the steps of moving amass of loose piece terminals over a transfer plate having bores thereinarranged in said pattern while maintaining a pressure differentialacross the transfer plate to seat individual terminals in properorientation in substantially all of the bores; inserting terminalsmanually into the remaining unfilled bores; positioning the filledtransfer plate against the circuit board with each bore in alignmentwith a circuit board hole; and moving the terminals from the transferplate and into the holes in the circuit board.

in the plate, moving a sweeper lightly engaging the plate back and forthacross the plate to dislodge misaligned terminals held against bores asa result of the pressure differential, and moving a sweeper spaced fromthe plate back and forth across the plate to break up clusters ofterminals held against the bores to load terminals into the bores.

1. Apparatus for loading terminals into bores formed in a flat platecomprising a transfer plate having terminal receiving bores formedthrough the thickness thereof and arranged in a desired pattern; atilted plate support engagable with the plate away from the bores; aloading chamber above the support and a vacuum chamber beneath thesupport; a vacuum source communicating with the vacuum chamber tomaintain the pressure in the vacuum chamber beneath that in the loadingchamber; a terminal transportation system including an entrance chambercoMmunicating with the loading chamber at the top of the support andhaving a lower floor forming an extension of the plate when mounted onthe support, a loose piece terminal trap, a terminal supply conduitextending from said trap to a mouth opening into the entrance chamber, aterminal return conduit joining the loading chamber at the bottom of thesupport to the trap, air pressure means for directing a flow of air pastsaid trap and through said supply conduit to pick up a number of loosepiece terminals and direct a stream of terminals through the mouth andinto the entrance chamber, and baffle means in the entrance chamber forspreading the stream of terminals across the width of the plate; and asweeping assembly including a sweeper engagable with the plate fordislodging misaligned terminals from the bores in the plate, a clusterbreaker, and means for moving said sweeper and cluster breaker back andforth across the plate.
 2. Apparatus as in claim 1 wherein said sweepercomprises a pair of closely spaced flexible flaps having edges engagingthe plate, and wherein said cluster breaker comprises a third flexibleflap located a distance nearer the mouth than the sweeper.
 3. Apparatusas in claim 1 including means for limiting the pressure differentialacross the board as terminals are loaded into the bores.
 4. Apparatusfor mounting terminals on a circuit board in a given pattern comprisinga loading chamber; a vacuum chamber communicating with said loadingchamber; a transfer plate having terminal receiving bores thereinarranged in said pattern; a plate support for locating the transferplate in the opening between the chambers; vacuum means for lowering thepressure in the vacuum chamber below that of the loading pressurewhereby terminals are drawn into the bores; transport means for flowinga stream of loose piece terminals through the loading chamber and acrossthe transfer plate; a flat flexible wiping flap in the loading chamberwith one edge thereof engaging the transfer plate; means for moving theflap back and forth across the transfer plate to dislodge misalignedterminals from bores in the plate; and press means for forcing terminalsfrom the transfer plate bores into holes in a circuit board. 5.Apparatus as in claim 4 including a cluster breaker movable with saidflap and spaced a distance above the transfer plate for breaking upclusters of terminals formed thereon.
 6. Apparatus as in claim 3including means for limiting the pressure differential across thetransfer plate as terminals are loaded into the bores therein. 7.Apparatus as in claim 4 wherein said transport means includes a closecconduit having a terminal receiving opening in the loading chamber toone side of the plate support, a terminal receiving trap, a terminalemitting opening at another side of the transfer plate support and meansfor flowing a stream of terminals from said opening in a directiontoward the transfer plate.
 8. Tooling for simultaneously staking aplurality of terminals to a circuit board in a given pattern comprisinga terminal loading terminal plate having a number of cylindrical boresformed through the thickness thereof and oriented in said pattern, eachbore having an increased diameter lead-in on one side of the terminalplate to permit an eyelet type terminal to be confined in the borewithin the thickness of the terminal plate with the cylindrical body ofthe terminal in the bore and the terminal flange extending beyond thebore and engaging the sides of the lead-in below the surface of theterminal plate; a punch plate on the lead-in side of the terminal plateincluding a plurality of punches, each punch having a cylindrical bodyaxially aligned with a bore in the terminal plate and having a diameterslightly less than the interior diameter of the bore, a reduced diameternose at the free end of the punch and a locating shoulder surroundingthe nose; and a staking plate on the opposite side of the terminal plateincluding a plurality of conical stakIng anvils, each staking anvilbeing axially aligned with a bore whereby upon positioning of a circuitboard between the terminal plate and the staking plate with a circuitboard hole in nominal alignment with the axis of each bore relativemovement of the punch plate toward the anvil plate moves the punchesinto engagement with the terminals, and forces the same through thebores while seated on the locating shoulders, positions the bodies ofthe terminals within circuit board holes with the major portion of eachflange seated against the top of the circuit board and stakes a majorportion of the free end of the eyelet body adjacent the bottom of thecircuit board.
 9. A method of mounting terminals on a circuit boardcomprising the steps of flowing a stream of loose piece terminals down atilted transfer plate while maintaining a pressure differential acrossthe plate to draw properly oriented individual terminals into bores inthe transfer plate, dislodging misaligned terminals held against boresas a result of the pressure differential, and breaking up clusters ofterminals held against bores to load nearly all of the bores withterminals; manually inserting properly oriented terminals into theremaining unloaded bores to completely load the transfer plate;positioning the transfer plate in a press adjacent a circuit board withcircuit board holes in alignment with the bores; and closing the pressto force the terminals from the transfer plate into the circuit boardholes.
 10. The method of mounting individual loose piece terminals inholes in a circuit board having a given pattern comprising the steps ofmoving a mass of loose piece terminals over a transfer plate havingbores therein arranged in said pattern while maintaining a pressuredifferential across the transfer plate to seat individual terminals inproper orientation in substantially all of the bores; insertingterminals manually into the remaining unfilled bores; positioning thefilled transfer plate against the circuit board with each bore inalignment with a circuit board hole; and moving the terminals from thetransfer plate and into the holes in the circuit board.
 11. The methodof claim 10 including the steps of dislodging misoriented terminals fromthe transfer plate bores and the breaking up of clusters of terminals onthe transfer plate.
 12. The method of mounting terminals on a platecomprising the steps of flowing a stream of loose piece terminals acrossthe top surface of a tilted plate while maintaining a pressuredifferential across the plate to draw properly oriented individualterminals into bores in the plate, moving a sweeper lightly engaging theplate back and forth across the plate to dislodge misaligned terminalsheld against bores as a result of the pressure differential, and movinga sweeper spaced from the plate back and forth across the plate to breakup clusters of terminals held against the bores to load terminals intothe bores.